/**
 * Prefix Sum
 * O(T): O(n)
 * O(S): O(1)
 * @param {number[]} nums
 * @return {number[]}
 */
var runningSum = function (nums) {
	for (let i = 1; i < nums.length; i++) {
		nums[i] = nums[i - 1] + nums[i];
	}
	return nums;
};
